Production of acid substances used in the production of carbon dioxide



Patented Jan. 19, 1932 ERNEST WALTER GEERE, F BEGKENHAM, ENGLAND PRODUCTION OF ACID SUBSTANCES USED IN THE PRODUCTION OF CARBON DIOXIDE No Drawing. Application filed September 4, 1928, Serial No. 303,960, and. in Great Britain September 9, 1927.

This my invention relates to the control or to a degree which cannot be attained without regulation of the production of carbon dioxmilling together. ide by the intimate admixture of a free acid I claim such as phosphoric, sulphuric, or any other A method of preparing carbon dioxide suitable liquid acid with a salt, e. g. phosevolving powders and the like, comprising 55 phates, the acid being addedin such quanticoating only a portion of the acid constituties that the acid salt is obtained holding tree cuts with a layer of a protecting medium and acid. incorporating the remainder of the acid con- The substance thus obtained is treated with stituents by milling in roller mills and the a medium such as a fat, wax, or hydrogenated like. 00

oil, whereby when in combination with a car- ERNEST WALTER GEERE. bonate and/or bi-carbonate the speed of the reaction is governed and carbon dioxide is not evolved in the desired quantities until a definite temperature is reached; this point can 65 be varied by the adoption and choice of a suitable medium, and a much less quantity of the acid substance is required to produce a given quantity of carbon dioxide than is required when the acid salt is made use of. i 70 The production of the acid substance is carried out in the following manners (a) In the usual process of the manufacture of acid salts, the acid is added in excess and the substance is then dehydrated. The 75 anhydrous mixture so produced is allowed to cool to a temperature just below the melting point of the medium used, when the medium which has previously been melted is v added, the whole being agitated and the temso perature maintained during the process.

(b) An acid or neutral salt is treated with the requisite quantity of a suitable acid by thorough agitation in the cold or under moderate heat. To the substance so produced the 85.

molten medium is added and treated in the aforesaid manner.

Definite quantities of untreated acid phosphates, acid sulphates, acid salts, etc., are

incorporated in the product so obtained, which quantities are variable in accordance with the quantity of medium employed as well as with the desired final acid content.

45 The incorporation is efiected in roller mills l and similar machines which cause the unprotected particles to enter into a mechanical union with the protected particles and the distribution of the protecting substance or 59 medium over the whole mass to be uniform 

